Non-contact temperature measurement sensor

ABSTRACT

The present disclosure is directed to a sensor package having a thermopile sensor and a reference (or dark channel) thermopile sensor disposed therein for temperature measurements. In one or more implementations, the sensor package includes a substrate, a thermopile sensor disposed over the substrate, a reference thermopile sensor disposed over the substrate, a reference temperature sensor disposed over the substrate surface, a lid assembly disposed over the thermopile sensor and the reference thermopile sensor, and a thermo-optical shield. The thermo-optical shield defines an aperture over the thermopile sensor such that at least a portion of the thermo-optical shield is positioned over the reference thermopile sensor to provide optical and thermal shielding for portions of the sensor package.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims the benefit under 35 U.S.C. § 119(e) ofU.S. Provisional Application Ser. No. 62/163,923, entitled NON-CONTACTTEMPERATURE MEASUREMENT SENSOR, filed May 19, 2015. U.S. ProvisionalApplication Ser. No. 62/163,923 is hereby incorporated by reference inits entirety.

BACKGROUND

Thermopile sensors convert thermal energy into electrical energy. Thesesensors may utilize several thermocouples to generate an output voltageproportional to a local temperature difference (e.g., a temperaturegradient). These thermopile sensors may be utilized in the medicalindustry to measure body temperature, in heat flux sensors, and/or gasburner safety controls.

SUMMARY

A sensor package is described having a thermopile sensor and a reference(or dark channel) thermopile sensor disposed therein. In one or moreimplementations, the sensor package includes a substrate, a thermopilesensor disposed over the substrate, a reference thermopile sensordisposed over the substrate, a reference temperature sensor disposedover the substrate surface, a lid assembly disposed over the thermopilesensor and the reference thermopile sensor, and a thermo-optical shield.The lid assembly includes a transparent structure that passeselectromagnetic radiation occurring in a limited spectrum of wavelengths(e.g., infrared radiation [IR]). The thermo-optical shield defines anaperture over the thermopile sensor such that at least a portion of thethermo-optical shield is positioned over the reference thermopilesensor. The thermo-optical shield is configured to at leastsubstantially block the electromagnetic radiation occurring in a limitedspectrum of wavelengths from reaching the reference thermopile sensor,and can be mounted within the sensor package, mounted to the lidassembly, or integrated into the lid assembly.

This Summary is provided to introduce a selection of concepts in asimplified form that are further described below in the DetailedDescription. This Summary is not intended to identify key features oressential features of the claimed subject matter, nor is it intended tobe used as an aid in determining the scope of the claimed subjectmatter.

DRAWINGS

The detailed description is described with reference to the accompanyingfigures. The use of the same reference numbers in different instances inthe description and the figures may indicate similar or identical items.

FIG. 1 is a partial cross-sectional side view illustrating a sensorpackage including a thermopile sensor, a reference thermopile sensor,and a reference temperature sensor disposed therein in accordance withan example implementation of the present disclosure.

FIG. 2 is a partial cross-sectional side view illustrating the sensorpackage shown in FIG. 1, where the thermopile sensor, the referencethermopile sensor, and the reference temperature sensor arecommunicatively connected to an application-specific integrated circuitin accordance with an example implementation of the present disclosure.

FIG. 3 is a partial cross-sectional side view illustrating a sensorpackage having an angled aperture disposed in a thermo-optical shield inaccordance with an example implementation of the present disclosure.

FIG. 4 is a partial cross-sectional side view illustrating a sensorpackage having a thermally-insulating layer as part of a lid assemblyabove the thermopile sensors in accordance with an exampleimplementation of the present disclosure.

FIG. 5 is a partial cross-sectional side view illustrating a sensorpackage having a thermally-insulating layer as part of a lid assemblyabove the thermopile sensors in accordance with an exampleimplementation of the present disclosure.

FIG. 6 is a partial cross-sectional side view illustrating a sensorpackage having a thermally-insulating layer integrated within the lidassembly in accordance with an example implementation of the presentdisclosure.

FIG. 7 is a chart illustrating noise versus time delay for variouspackage configurations in accordance with example implementations of thepresent disclosure.

DETAILED DESCRIPTION

Overview

Thermopile sensors are utilized in a variety of applications. Forexample, a thermopile is an infrared radiation (IR) detector (e.g.,electromagnetic radiation) that can be used for making non-contacttemperature measurements. A thermopile can include several thermocouplescoupled together. Thermopiles are used to provide an output in responseto temperature as part of a temperature measuring device, such as ininfrared thermometers, used to measure body temperature. Whilethermopiles detect electromagnetic radiation from an object of interest,the thermopiles can also detect electromagnetic radiation from otherobjects that are not of interest. Also, a thermopile outputs a voltagethat depends on the temperature difference of an object or environmentand its own temperature. Thus, a reference temperature sensor may beutilized to determine an object's temperature, an ambient temperature,or the like. Further, a sensor package can include its own temperaturegradients throughout the structure of the sensor, which can affecttemperature readings from one thermopile relative to another thermopile.

Therefore, a sensor package is described having a thermopile sensor anda reference (or dark channel) thermopile sensor disposed therein. In oneor more implementations, the sensor package includes a substrate, athermopile sensor disposed over the substrate, a reference thermopilesensor disposed over the substrate, a reference temperature sensordisposed over the substrate surface, a lid assembly disposed over thethermopile sensor and the reference thermopile sensor, and athermo-optical shield. The lid assembly includes a transparent structurethat passes electromagnetic radiation occurring in a limited spectrum ofwavelengths (e.g., infrared radiation [IR]). The thermo-optical shielddefines an aperture over the thermopile sensor such that at least aportion of the thermo-optical shield is positioned over the referencethermopile sensor. The thermo-optical shield is configured to at leastsubstantially block the electromagnetic radiation occurring in a limitedspectrum of wavelengths from reaching the reference thermopile sensor,and can be mounted within the sensor package, mounted to the lidassembly, or integrated into the lid assembly. For example, thethermo-optical shield at least substantially prevents electromagneticradiation emitted from an object of interest to reach the referencethermopile sensor, and at least substantially obscures variations in thetemperature of the lid assembly from the fields of view of thethermopile sensors.

Example Implementations

FIG. 1 illustrates an example sensor package 100 in accordance with anexample implementation of the present disclosure. As shown, the sensorpackage 100 includes a thermopile sensor 102 that senses electromagneticradiation transfer between the thermopile sensor 102 and an object or anambient environment. For example, an object emits electromagneticradiation having a wavelength characteristic according to itstemperature. More specifically, the radiation has a wavelength rangethat depends on the temperature of the object or environment. Thethermopile sensor 102 senses changes in electromagnetic radiationtransfer and translates the electromagnetic radiation change into acorresponding electrical signal (e.g., converts thermal energy intocorresponding electrical energy). For instance, the thermopile sensor102 translates the electromagnetic radiation change into a correspondingvoltage signal. In implementations, the thermopile sensor 102 detectselectromagnetic radiation having a first limited spectrum of wavelengths(e.g., wavelengths between a first wavelength and a second wavelength).For example, the thermopile sensor 102 is configured to detectelectromagnetic radiation occurring within the infrared spectrum. Insome implementations, the thermopile sensor 102 includes an absorber toimprove the efficiency of the electromagnetic radiation absorption.

As shown, the thermopile sensor 102 is positioned over a substrate 104.The sensor package 100 includes support structure. For example, as shownin FIG. 1, a first wall structure 106 and a second wall structure 108are employed adjacent to the substrate 104 to at least partially enclosethe thermopile sensor 102. The substrate 104 and the wall structures106, 108 comprise material that at least substantially prevents thetransmission of radiation. For example, the substrate 104 and the wallstructures 106, 108 may comprise metal materials, metallic alloys, andceramic materials, such as glass, SiO₂, AlN, and/or Al₂O₃. In someimplementations, the substrate 104 comprises a printed circuit board(PCB). The first wall structure 106 and the second wall structure 108are illustrated for example purposes. However, it is understood that thesupport structure may employ multiple wall structures that may beconjoined to enclose the components of the sensor package, where thesupport structure can include the substrate 104 as a unitaryconstruction. The support structure may be utilized to selectively blockelectromagnetic radiation from entering the sensor package 100. Thesupport structure may also function as a hermetic seal to at leastsubstantially prevent air from entering the sensor package 100.

As shown in FIG. 1, the sensor package 100 includes a referencetemperature sensor 110 and a reference thermopile sensor 112. Thereference temperature sensor 110 may be positioned over the substrate104 and adjacent to the thermopile sensor 102 and the referencethermopile sensor 112. As discussed herein, the thermopile sensor 102detects electromagnetic (e.g., infrared) radiation exchange associatedthe components within the sensor package 100 and an external object orenvironment. The reference thermopile sensor 112 is configured to detectthe electromagnetic (e.g., infrared) radiation associated with thecomponents within the sensor package 100. The signal from the thermopilesensor 102 can be processed (e.g., a subtraction protocol) to removesignal components that are the same as those resulting from thereference thermopile sensor 112 to provide a signal that represents atemperature of the external object or environment. The signal processingmay occur within the digital domain or the analog domain. For example,an electrical signal that is common to the thermopile sensor 102 and thereference thermopile sensor (e.g., an electrical signal that representsan electromagnetic radiation associated with the sensor package) can beremoved to generate a signal that represents a temperature of theexternal object or environment. In some instances, the thermopile sensor102 and the reference thermopile sensor 112 may be integrated togetheron the same integrated circuit die. In another instance, the thermopilesensor 102 and the reference thermopile sensor 112 may be separatesensors (e.g., fabricated as standalone die). Additionally, in someimplementations, the reference temperature sensor 110 may also beincorporated on or integrated with the standalone die having thethermopile sensor 102 and the reference thermopile sensor 112. Thereference temperature sensor 110 may comprise a resistive temperaturedetector (RTD), a complementary metal-oxide semiconductor basedtemperature sensor, a thermistor, an integrated bandgap voltagereference, a thin film resistor, or any sensor that converts absolutetemperature to an electrically measured signal.

In an implementation, the reference temperature sensor 110 detectssignals that relate to the temperature reference for the thermopilesensor 102 and the reference thermopile sensor 112. For example, asshown in FIG. 1, the sensor package 100 includes a transparent structure114 positioned over the thermopile sensor 102, the reference temperaturesensor 110, and the reference thermopile sensor 112. Together, thesubstrate 104, the support structure (e.g., illustrated as wallstructures 106, 108), and the transparent structure 114 at leastpartially comprises a package that encloses the thermopile sensor 102and the reference temperature sensor 110. In implementations, thetransparent structure 114 is configured to pass electromagneticradiation occurring within the limited spectrum of wavelengths (e.g.,infrared radiation) and to filter light occurring having a wavelengthnot within the limited spectrum of wavelengths. In some embodiments, thetransparent structure 114 comprises silicon. As shown, the sensorpackage 100 includes a thermo-optical shield 116 positioned between thetransparent structure 114 and the thermopile sensors (e.g., thethermopile sensor 102 and the reference thermopile sensor 112). Thethermo-optical shield 116 is configured to at least substantiallyprevent transmission of the electromagnetic radiation occurring withinthe limited spectrum of wavelengths (as well as other strayelectromagnetic radiation). Further, the thermo-optical shield 116 isconfigured to at least substantially obscure variations in thetemperature of portions of the sensor package 100 from the fields ofview of the thermopile sensors (e.g., the thermopile sensor 102 and thereference thermopile sensor 112).

The thermo-optical shield 116 includes a thermal insulation layer 118and an electromagnetic blocker 120. The thermal insulation layer 118 cancomprise a material that is configured to at least substantially obscurevariations in the temperature of portions of the sensor package 100 fromthe fields of view of the thermopile sensors (e.g., the thermopilesensor 102 and the reference thermopile sensor 112) and can include, forexample a gaseous material (e.g., an air gap, as shown in FIG. 1), athermally-insulating dielectric material (e.g., silicon oxide,polyamide, or so forth). The electromagnetic blocker 120 can comprise asuitable electromagnetic blocking material, such as a metallic material,a silicon material, a germanium material, a ceramic, a glass, apolymeric material, or the like. In one or more implementations, thetransparent structure 114, the thermal insulation layer 118, and theelectromagnetic blocker 120 form a lid assembly (examples of which areprovided in FIGS. 4-6). While FIG. 1 shows the thermo-optical shield 116positioned between the transparent structure 114 and the thermopilesensors, other configuration are possible, including, but not limitedto, the thermo-optical shield 116 being mounted to the lid assembly orintegrated into the lid assembly, such that the transparent structure114 can be positioned between at least a portion of the thermo-opticalshield 116 and the thermopile sensors.

The sensor package 100 can include an optical aperture positioned on aninterior surface of the transparent structure 114 to define or assist indefining a field of view of the thermopile sensors. For example, in animplementation, the sensor package 100 includes an aperture layer 122positioned on an interior surface 124 of the transparent structure 114,the aperture layer 122 defining an aperture 126 positioned at leastapproximately over the thermopile sensor 102, such that electromagneticradiation may be transmitted from an external object or environment tothe thermopile sensor 102 while at least substantially preventing thetransmission of the electromagnetic radiation from the object orenvironment to the reference thermopile sensor 112. The aperture layer122 can comprise materials configured to define or assist in definingthe field of view of the thermopile sensors. For example, inimplementations, the aperture layer 122 comprises on or more layers oftitanium-tungsten (Ti—W), chrome, copper, aluminum, silicon oxide,alloys and oxides thereof, or combinations thereof. The electromagneticblocker 120 can similarly define an aperture to mirror aperture 126 overthe thermopile sensor 102. As shown in FIG. 1, the electromagneticblocker 120 is thermally insulated from the transparent structure 114and the aperture layer 122 by the thermal insulation layer 118. As such,the electromagnetic blocker 120 may not display substantial thermalgradients, such as those that can be present in a lid assembly of thesensor package (shown in FIG. 2).

In some implementations, the sensor package 100 may include a lens 128to focus electromagnetic radiation incident upon the lens 128. Forexample, the lens 128 may shape (e.g., collimate) the electromagneticradiation incident upon the lens 128 and to transmit the electromagneticradiation to the thermopile sensor 102 (e.g., to the membrane of thethermopile sensor 102). The lens 128 may comprise silicon or othersuitable material, and may comprise the same or different material asthe transparent structure 114.

Referring to FIG. 2, a lateral temperature gradient is shown on the lidassembly (e.g., laterally across at least the transparent material 114).Such temperature gradient can be induced from air flow, energy sources,or so forth acting on and across external surfaces of the sensor package100. In the absence of the thermo-optical shield 116, the thermopilesensor 102 and the reference thermopile sensor 112 could sample the lidassembly differently, due to the lateral temperature gradient.Accordingly, the thermo-optical shield 116 thermally andelectromagnetically insulates the thermopile sensor 102 and thereference thermopile sensor 112 from the transparent material 114(including temperature gradients therethrough). The sensor package 100can also have temporal variations in temperature. For instance, in thecase that the thermopile sensor 102 and the reference thermopile sensor112 are read out at different times, the temperature of the sensorpackage 100 measured by the thermopile sensor 102 and the referencethermopile sensor 112 can be different. This temporal variance canintroduce error during the subtraction of the reference signal of thereference thermopile sensor 112 from the signal of the thermopile sensor102. Accordingly, in implementations, the output signals from thethermopile sensor 102 and the reference thermopile sensor 112 are readsynchronously.

For example, in one or more implementations, integrated circuitry 200(an application-specific integrated circuit) may be employed to generatea digital signal representing the electromagnetic radiation emitted froman external object or environment (e.g., determine a temperatureassociated with the object/environment). For example, theapplication-specific integrated circuit 200 may comprise a module thatis electrically connected to the sensor package 100 to receive theelectrical signals generated by the thermopile sensor 102 and thereference temperature sensor 112 in response to the electromagneticradiation occurring within the limited spectrum of wavelengths. Inimplementations, the circuitry may comprise analog-to-digital convertercircuitry, programmable-gain amplifier (PGA) circuitry, fixed-gainamplifier circuitry, combinations thereof, or the like. Theapplication-specific integrated circuit 200 is configured to receive theelectrical signal from the thermopile sensor 102, the electrical signalfrom the reference temperature sensor 110, and the electric signal fromthe reference thermopile sensor 112 to generate a signal representing atemperature associated with an external object or environment. Inimplementations, the application-specific integrated circuit 200 isconfigured to synchronously sample the electrical signal from thethermopile sensor 102 and the electric signal from the referencethermopile sensor 112 to reduce or substantially eliminate errorassociated with a lateral temperature gradient across the sensor package100. For example, the application-specific integrated circuit 200 isconfigured to remove (e.g., subtract) the electrical signal that iscommon to both electrical signals (e.g., the electrical signal thatrepresents the electromagnetic radiation associated with the package)and generate a signal that represents the temperature associated withthe object or environment. In implementations, the application-specificintegrated circuit 200 is configured to generate a digital signalrepresenting the temperature associated with the object or environment.In an implementation, the application-specific integrated circuit 200may store calibration parameters to generate corresponding digitalcalculations.

When light is received by an aperture of a material, the light canimpact sidewall portions of the aperture, causing light to reflect offthe material of the sidewall portions. Where a sensor is disposed belowthe aperture, the reflection of the light can adversely impact theoptics of the sensor (e.g., the field of view of the sensor). Referringto FIG. 3, the sensor package 100 includes an aperture 126 having angledsidewalls 300 (angled sidewalls 300 a and 300 b are shown) disposed in athermo-optical shield in accordance with an example implementation ofthe present disclosure. The angled sidewalls 300 can be angled toreflect light away from the interior of the sensor package 100 (e.g.,away from the thermopile sensor 102). In implementations, the reflectedlight is reflected into the cavity between the electromagnetic block 120and the transparent material 114, where the reflected light canultimately be absorbed, scattered, or the like. In one or moreimplementations, the angled sidewalls 300 include an angle from thehorizontal (e.g., x-axis) of about 45 degrees or shallower, as shown inFIG. 3. In another example embodiment of the disclosure, the angledsidewalls 300 may include an angle of between about 45 degrees and about1 degree from horizontal (e.g., x-axis). In one or more implementations,the sensor package 100 can include a non-reflecting material in aninterior of the sensor package 100 to mitigate the adverse impact oflight reflection within the sensor package 100. For example, thethermo-optical shield 116 can comprise a non-reflecting material, can beat least partially coated with a non-reflecting material, or so forth.Examples of non-reflecting materials include, but are not limited to,glass, coated silicon, particulate coatings of low fill factor, lowdensity metals (e.g., particulate bismuth, particulate silver,particulate gold), titanium tungsten, or so forth.

Referring to FIGS. 4 and 5, a sensor package 100 includesthermally-insulating layer 118 as part of a lid assembly 400 above thethermopile sensors in accordance with an example implementation of thepresent disclosure. The lid assembly 400 includes thethermally-insulating layer 118 and can include an electromagneticblocker 120 as part of a thermo-optical shield 116. The lid assembly 400can be affixed, mounted, or the like, to the supporting structure of thesensor package 100 (shown as 402), such as via an adhesive (e.g., anepoxy), a glass, a metal, or a metal alloy (e.g., a solder). As shown inFIG. 5, the thermo-optical shield 116 can define apertures 500 adjacentthe first wall structure 106 and the second wall structure 108 of thesensor package 100. In implementations, the apertures 500 facilitateadhesion of the lid assembly directly to the sensor package structure(e.g., via the first wall structure 106 and the second wall structure108), while maintaining separation of the bonding/affixing region 402and the thermo-optical shield 116, particularly in implementations wherethe thermo-optical shield 116 comprises materials that are less robustthan those forming the transparent material 114. As shown, thethermo-optical shield 116 remains above the reference temperature sensor112 to substantially block the electromagnetic radiation occurring in alimited spectrum of wavelengths from reaching the reference thermopilesensor 112, and to thermally isolate the temperature of the lid assemblyfrom the field of view of the reference thermopile sensor 112.

Referring to FIG. 6, a sensor package 100 is shown having a thermalinsulation layer 118 integrated within a lid assembly 600 in accordancewith an example implementation of the present disclosure. The lidassembly 600 includes a transparent structure 114, a barrier layer 602,and the thermal insulation layer 118 positioned between the transparentstructure 114 and the barrier layer 602. In one or more implementations,the barrier layer 602 includes a glass barrier material or a siliconbarrier material. The barrier layer 602 can further define an aperture126, such as when the barrier layer 602 comprises a glass barriermaterial.

In some implementations, the sensor package 100 includes a berm (e.g.,barrier) structure that would be configured to mitigate electromagneticradiation that entered through the aperture 126 to reach the referencethermopile sensor 112. The berm structure may comprise any suitablematerial that prevents transmission of electromagnetic radiation withinthe limited spectrum of wavelengths. The berm may be a structure that ismounted or affixed through a suitable epoxy process to the lid assembly.In some implementations, the berm serves as a structure to partition asensor cavity into multiple sections (e.g., a first section includingthe thermopile sensor 102 and a second section including the referencethermopile sensor 112). In some implementations, the berm may be mountedto substrate 104 or may be a part of the reference temperature sensor110.

Referring to FIG. 7, a chart is shown illustrating the impact ofsynchronous sampling 700 of the electrical signal from the thermopilesensor 102 and the electric signal from the reference thermopile sensor112, and also the impact of the thermo-optical shield on noise of theoverall sensor package. As shown, when the thermo-optical shieldincludes an air gap (e.g., thermally-insulating layer 118) and anadditional solid layer (e.g., electromagnetic blocker 120), shown as702, the noise is minimized with respect to barriers incorporating adielectric material disposed directly on a silicon lid, shown as 704, ora package having no thermo-optical layer (i.e., only have a siliconlid), shown as 706.

CONCLUSION

Although the subject matter has been described in language specific tostructural features and/or process operations, it is to be understoodthat the subject matter defined in the appended claims is notnecessarily limited to the specific features or acts described above.Rather, the specific features and acts described above are disclosed asexample forms of implementing the claims.

What is claimed is:
 1. A sensor package comprising: a substrate; a thermopile sensor disposed over the substrate; a reference thermopile sensor disposed over the substrate; a reference temperature sensor disposed over the substrate and adjacent to the thermopile sensor and the reference thermopile sensor; a lid assembly disposed over the thermopile sensor, the reference thermopile sensor, and the reference temperature sensor, the lid assembly comprising a transparent structure that passes electromagnetic radiation occurring in a limited spectrum of wavelengths; and a thermo-optical shield, at least a portion of which is positioned between the transparent structure and one or more of the thermopile sensor, the reference thermopile sensor, or the reference temperature sensor, wherein the thermo-optical shield includes a thermal insulation layer and an electromagnetic blocker.
 2. The sensor package as recited in claim 1, wherein the thermal insulation layer comprises at least one of an air gap or a dielectric material.
 3. The sensor package as recited in claim 1, wherein the thermo-optical shield defines an aperture positioned over at least a portion of the thermopile sensor.
 4. The sensor package as recited in claim 1, further comprising: an aperture layer positioned between the transparent structure of the lid assembly and at least a portion of the thermo-optical shield, the aperture layer including a metallic material defining an aperture positioned over at least a portion of the thermopile sensor.
 5. The sensor package as recited in claim 1, wherein the electromagnetic blocker comprises at least one of a silicon material, a germanium material, a metallic material, a ceramic, or a glass.
 6. The sensor package as recited in claim 5, wherein the electromagnetic blocker comprises an oxide of silicon.
 7. The sensor package as recited in claim 1, further comprising a support structure disposed about the substrate for supporting the lid assembly.
 8. The sensor package as recited in claim 7, wherein the aperture includes angled sidewalls.
 9. The sensor package as recited in claim 8, wherein the angled sidewalls include an angle of between about 45 degrees and about 1 degree from horizontal.
 10. A system comprising: a sensor package, the sensor package comprising: a substrate; a thermopile sensor disposed over the substrate; a reference thermopile sensor disposed over the substrate; a reference temperature sensor disposed over the substrate and adjacent to the thermopile sensor and the reference thermopile sensor; a lid assembly disposed over the thermopile sensor, the reference thermopile sensor, and the reference temperature sensor, the lid assembly comprising a transparent structure that passes electromagnetic radiation occurring in a limited spectrum of wavelengths; and a thermo-optical shield, at least a portion of which is positioned between the transparent structure and one or more of the thermopile sensor, the reference thermopile sensor, or the reference temperature sensor; and application-specific integrated circuitry in electrical communication with the sensor package, the application-specific integrated circuitry configured to generate an electrical signal corresponding to electromagnetic radiation detected by the sensor package, wherein the thermo-optical shield includes a thermal insulation layer and an electromagnetic blocker.
 11. The system as recited in claim 10, wherein the thermal insulation layer comprises at least one of an air gap or a dielectric material.
 12. The system as recited in claim 10, further comprising a support structure disposed about the substrate for supporting the lid assembly.
 13. The system as recited in claim 10, further comprising: an aperture layer positioned between the transparent structure of the lid assembly and at least a portion of the thermo-optical shield, the aperture layer including a metallic material defining an aperture positioned over at least a portion of the thermopile sensor.
 14. The system as recited in claim 10, wherein the application-specific integrated circuitry is further configured to synchronously sample an electrical signal from the thermopile sensor and an electric signal from the reference thermopile sensor.
 15. The system as recited in claim 10, wherein the electromagnetic blocker comprises at least one of a silicon material, a germanium material, a metallic material, a ceramic, or a glass.
 16. The system as recited in claim 15, wherein the electromagnetic blocker comprises an oxide of silicon.
 17. The system as recited in claim 10, wherein the thermo-optical shield defines an aperture positioned over at least a portion of the thermopile sensor.
 18. The system as recited in claim 17, wherein the aperture includes angled sidewalls.
 19. The system as recited in claim 18, wherein the angled sidewalls include an angle of between about 45 degrees and about 1 degree from horizontal. 